Elena shrugged. “Density is mass over volume. If there are air bubbles, you have less alcohol in the same space. So you measure a lower mass. Therefore, your calculated density is lower than the truth.”
“You didn’t degas it,” she said.
Elena, bored with her summer reading, peered over his elbow. “So? That’s basically the same.”
“No,” Mateo groaned. “Professor Almeida has a laser eye. If it’s not perfect to the third decimal, he’ll know I rushed the meniscus reading.”